<template>
  <div>
    <div class="goods">
      <div class="menu-wrapper">
        <ul>
          <!--current-->
          <li class="menu-item" v-for="(good, index) in shopGoods" :key="index"
              :class="{current: index===currentIndex}" @click="clickMenuItem(index)">
            <span class="text bottom-border-1px">
              <img class="icon" :src="good.icon" v-if="good.icon">
              {{good.name}}
            </span>
          </li>
        </ul>
      </div>
      <div class="foods-wrapper">
        <ul ref="foodsUl">
          <li class="food-list-hook" v-for="(good, index) in shopGoods" :key="index">
            <h1 class="title">{{good.name}}</h1>
            <ul>
              <li class="food-item bottom-border-1px" v-for="(food, index) in good.foods"
                  :key="index" @click="showFood(food)">
                <div class="icon">
                  <img width="57" height="57" :src="food.icon">
                </div>
                <div class="content">
                  <h2 class="name">{{food.name}}</h2>
                  <p class="desc">{{food.description}}</p>
                  <div class="extra">
                    <span class="count">月售{{food.sellCount}}份</span>
                    <span>好评率{{food.rating}}%</span>
                  </div>
                  <div class="price">
                    <span class="now">￥{{food.price}}</span>
                    <span class="old" v-if="food.oldPrice">￥{{food.oldPrice}}</span>
                  </div>
                  <div class="cartcontrol-wrapper">
                    <CartControl :food="food"/>
                  </div>
                </div>
              </li>
            </ul>
          </li>
        </ul>
      </div>
      <ShopCart/>
    </div>
    <Food :food="food" ref="food"/>
  </div>
</template>

<script>

import {mapState} from "vuex";
import CartControl from "@/components/CartControl/CartControl";
import Food from "@/components/Food/Food";
import BScroll from 'better-scroll'
import ShopCart from "@/components/ShopCart/ShopCart"
export default {
  name: "ShopGoods",
  data() {
    return {
      scrollY: 0, // 右侧滑动的Y轴坐标 (滑动过程时实时变化)
      tops: [], // 所有右侧分类li的top组成的数组  (列表第一次显示后就不再变化)
      food: {}, // 需要显示的food
      // isShowFood:false
    }
  },
  mounted() {

    this.$store.dispatch('getShopGoods', () => {
      this.$nextTick(() => {
        this._initScroll()
        this._initTops()
      })
    })


  },
  computed: {
    ...mapState(['shopGoods']),
    // 计算得到当前分类的下标
    currentIndex() {// 初始和相关数据发生了变化
      // 得到条件数据
      const {scrollY, tops} = this
      // 根据条件计算产生一个结果
      const index = tops.findIndex((top, index) => {
        // scrollY>=当前top && scrollY<下一个top
        return scrollY >= top && scrollY < tops[index + 1]
      })
      // 返回结果
      return index
    }
  },
  methods: {
    // 初始化滚动
    _initScroll() {
      // 列表显示之后创建
      new BScroll('.menu-wrapper', {
        click: true
      })
      this.foodsScroll = new BScroll('.foods-wrapper', {
        probeType: 2,  // 因为惯性滑动不会触发
        click: true
      })

      // 给右侧列表绑定scroll监听
      this.foodsScroll.on('scroll', ({x, y}) => {
        // console.log(x, y)
        this.scrollY = Math.abs(y)
      })
      // 给右侧列表绑定scroll结束的监听
      this.foodsScroll.on('scrollEnd', ({x, y}) => {
        // console.log('scrollEnd', x, y)
        this.scrollY = Math.abs(y)
      })

    },
    // 初始化tops
    _initTops() {
      // 1. 初始化tops
      const tops = []
      let top = 0
      tops.push(top)
      // 2. 收集
      // 找到所有分类的li
      const lis = this.$refs.foodsUl.getElementsByClassName('food-list-hook')
      Array.prototype.slice.call(lis).forEach(li => {
        top += li.clientHeight
        tops.push(top)
      })
      // 3. 更新数据
      this.tops = tops
    },
    clickMenuItem(index) {
      // console.log(index)
      // 使用右侧列表滑动到对应的位置

      // 得到目标位置的scrollY
      const scrollY = this.tops[index]
      // 立即更新scrollY(让点击的分类项成为当前分类)
      this.scrollY = scrollY
      // 平滑滑动右侧列表
      this.foodsScroll.scrollTo(0, -scrollY, 300)
      // console.log(this.food)
    },

    //显示点击的food
    showFood(food) {
      // 设置food
      this.food = food
      // 显示food组件 (在父组件中调用子组件对象的方法)
      this.$refs.food.toggleShow()

    }
    // toShow(){
    //   this.isShowFood=!this.isShowFood
    // },
    // showFood(food) {
    //   // 设置food
    //   this.food = food
    //   this.toShow()
    //   // 显示food组件 (在父组件中调用子组件对象的方法)
    //   // this.$refs.food.toggleShow()
    //
    // }
  },
  components:{
    CartControl,
    Food,
    ShopCart
  }
}
</script>

<style scoped lang="stylus">
@import "../../../common/stylus/mixins.styl"
.goods
  display: flex
  position: absolute
  top: 195px
  bottom: 46px
  width: 100%
  background: #fff;
  overflow: hidden

  .menu-wrapper
    flex: 0 0 80px
    width: 80px
    background: #f3f5f7

    .menu-item
      display: table
      height: 54px
      width: 56px
      padding: 0 12px
      line-height: 14px

      &.current
        position: relative
        z-index: 10
        margin-top: -1px
        background: #fff
        color: $green
        font-weight: 700

        .text
          border-none()

      .icon
        display: inline-block
        vertical-align: top
        width: 12px
        height: 12px
        margin-right: 2px
        background-size: 12px 12px
        background-repeat: no-repeat

      .text
        display: table-cell
        width: 56px
        vertical-align: middle
        bottom-border-1px(rgba(7, 17, 27, 0.1))
        font-size: 12px

  .foods-wrapper
    flex: 1

    .title
      padding-left: 14px
      height: 26px
      line-height: 26px
      border-left: 2px solid #d9dde1
      font-size: 12px
      color: rgb(147, 153, 159)
      background: #f3f5f7

    .food-item
      display: flex
      margin: 18px
      padding-bottom: 18px
      bottom-border-1px(rgba(7, 17, 27, 0.1))

      &:last-child
        border-none()
        margin-bottom: 0

      .icon
        flex: 0 0 57px
        margin-right: 10px

      .content
        flex: 1

        .name
          margin: 2px 0 8px 0
          height: 14px
          line-height: 14px
          font-size: 14px
          color: rgb(7, 17, 27)

        .desc, .extra
          line-height: 10px
          font-size: 10px
          color: rgb(147, 153, 159)

        .desc
          line-height: 12px
          margin-bottom: 8px

        .extra
          .count
            margin-right: 12px

        .price
          font-weight: 700
          line-height: 24px

          .now
            margin-right: 8px
            font-size: 14px
            color: rgb(240, 20, 20)

          .old
            text-decoration: line-through
            font-size: 10px
            color: rgb(147, 153, 159)

        .cartcontrol-wrapper
          position: absolute
          right: 0
          bottom: 12px
</style>